Vulcanization of rubber



Chester W. Christensen, Akron; pastas; I

"i m ju Service a qr torieslfinmnany n A p o A st io; corp at o 9 Obie "so Drawing- Application ,0ctober 5 1932,1; w it i 1-14 Claims;

-pThe' present invention is directed to thet'art 'of producing vulcanized rubber. The an invention is particularly concerned with a process of vulcanizing "rubber? wherein a new class "rofrncom- "pounds obtained as hereinafter. described and possessing desirable characteristics forthe use described; is employed as an" accelerator soft the vulcanization process. Then invention will .be

a Thepreferrednew classof" accelerators comprises the compounds produced byfurthertreat ling with; anqgorg'anic acid the carbon disulfide ;-=derivative;' of the reaction product of an. aldehyde and an aliphatic" cyclic secondary ,am'ine. The

tion wherein thenovelty of readily understood from the following specificaset forth and described.

reaction products indicated above are rapid and strong accelerators. Furthermore, testshave -shown1that thefpreferred class of accelerators are fasteriin their curing action than the corresponding carbon'fdisulfide derivative of the re- 7 action product of an aldehyde andan aliphatic rcy'clic secondary a rline" unreactedrv-with an; or-

ganic acid? l V l 1 'For example the following substances are typical members of the class :of materials outlined above: the phthalic acidderivative of the product formed by reacting substantially equi-molec- -u1ar proportions of methylene: dipiperidine and t carbon disulfide;"the oxalicl acid derivative "of v the product former-by" reacting substantially -equi-mo1ecular 3 proportions of methylene div piperidineland carbon disulfide; the actic acid derivative of the product formed by reacting"sub- .stantially equi-molecular'proportions of methyl- *ene dipiperidine and carbon'disulfide -the benzoic "acid derivative 'of 'the reaction productfof substantially equi-moleoular' proportions of butyle- "dene 'dipiperidine' and-'Pcarbon disulfide; [the l "phthali'c acid'fierivative of the reaction product A a of substantially. equi-molecular proportions of. heptylidene dipiperidirie and arbori disulfide; I the oxalic acid derivative of the product formed by reacting-substantially equi molecular proporg; Ztio'ns of'carbon disulfide and theproduct formed by reactingf substantially two molecular propor- "tions'of pipridine and substantially one molecular proportion of croton'aldehyde; the phthalic acid' 'derivativ of =the reaction product of i sub-- stantially equi-molecular proportions of methyln.:djpipe coline and carbon' disul'fidei 'th oxalic .1 acid derivative] of the reactioni product of substantially equi-molecular proportions fof rnethylq 5 l "I'l'1e oxalic' acid derivative of the reaction prodene dipipecoline and carbon disulfide the succinic acid" derivative of the reactionproduotof the process is full aqueou s which was incorporated inthe well "nor in a rubber stock comprising n substantially equi-rnolecular proportions of car- 'bon'disulfide and methylenedi alpha pipecoline and analogous pfodu tg; H l

W'I 'he following examples embodiments of thepresent invention and not limitations olution-fl of formaldehyde was j added pleted the water formed was separated; the reaction product driediandi'substantially one molecular proportion of 2130. disulfide added to h i fi y n d ib i ifie'6 Qb m a m- Iperatureljof substantiallyjffioifto 48 C. To the i carbon vdisulfide derivative produced thereby subjlistantially one mom'euia'rg prbpu uo of phthalic acid added thereto thelmixture heated on 'a's"teambath. A'viscous resin waslfforined known manlfittlt a he rubber sto lslr u lcompound wasyvul- The"testdatafollow in Table 1;; w s! canized'andthelvulcanizedjrubberiproducttested.

steam j pressure 3 asses Substantially one molecu r distortion car an 'slowlyi gl substant1ally twat-molecular proport1ons of piperidine at ;a-f temperature of substana act of substantiallyequi-molecularproportions of I tially to 41 0. After the reaction was commethylene dipiperidine and carbon disulfide was produced in a manner analogous to that employed for Example I except that substantially one-half a molecular proportion of oxalic acid was emticularily adapted for use at the lower temperature cures.

Obviously, the practice of this invention is not limited to the specific compositions given above,

ployed instead of one molecular proportion of ch Compositions being merely illustrative of 5 phthalic acid as set forth therein. The product methods of emp y the acceleratOTS Of this so obtainedwasincorporated in the usual manner v i n- -T p es t i vent n is l mited olein a rubbrstockicomprising a 1y by the appended claims wherein it is intended Y t to claim the invention as broadly as possible in P 1 bb f f g view of the prior art. 10

. e q ru er What is claimed is:

Zmc -fl-w-r-ifi- 1 iiAprbcssor treating rubber which comprises Sulfur heating rubber and sulfur in the presence of an Red 9 v. accelerator comprising an organic acid deriva- Steam: acld "uve'of the productiormed by reacting substan- 15 Accelerator 'f' -"f' tiallly e(f ui rr ltileciilar proportions of carbon di- The rubber Stock so uhfi dwgg fli fi 1 1: qmqeand the reaction product of substantially canized and the vulcanized rubber product tested" F 0116 molecular Proportion of an aliphatic a with the following results, hydeand substantially two molecular propor- 20 tions of an aliphatic cyclic secondary amine. 20

' H T b"? i :2. A process of treatingvrubber-which com- V l b n J prises heating rubber and sulfur in the. presence Cum fiei i of an accelerator comprising an organic acid p i l1 i i 'T fiw Ultimate derivative-of the'product formed by reacting 525" 1 v 1 b ee s lo s substantially equii-molecularproportions ofcar- 125 i E3 300% 500% 700% tbs/m v.bonadisulfidef-and the' reaction' product of subpressure i ri tstantiallyw-onecmolecularproportion of'an alip phatic aldehyde and substantially two molecular "202 973 2,370 880 proportions-Jof-a piperidinei l a 33,2 p "3. A process of treating rubber which com- 13!) 519 1:880 31,420 820 prises heating rubber and sulfur-in the presence 2% 2% .of 'an accelerator comprisingan aliphatic organic acid derivative of the product formed by reactsingysubstantially equi+molecular proportions of U v carbon disulfide and the reaction product of -=3'5 3 0f, hQI65 fi l substantially onemolecular-proportion-of .an all- 11 9 ot n ial r q o c l P P SO' phatic aldehydeiand substantially two =molecular 'me hylenedipi erid ea d arbo d flfi fl a xproportions of-acpipe'ridine. "p d cedi a'mali le ei e s t at pl yed 4=.-A.process ottreatinarubber which. com- :40 thepreparatipn 0t E am e The' lb t n -prises sheating rubber and sulfur thexpresence e40 :Q d- Q m t t of anaccelerator comprising the aceticacid de- "p 0 r W i rivative ofvtheproduct formedby reacting 's'ubr Parts stantially :equi-molecularproportions of carbon Bale crepe rubber "100 disulfide and methylene dipiperidine. I 5-. Aprocessiofrtreating rubber which comprise F v r bber-s rew cured and thecured 'rubberproducttested with results given in Table III.

T'dbZe'III Cure Mdduliis' olela'sticity in v 'lbs/inhtelonghtionspfir Tensileat Ultimate 0. is e 5 "2 's;- z i s. sin on a .7 steam 73007 5007 7007: I mms. pressure "v v i r 0 s45 1, 285 3,000 805 .151 410 51,508 3,040 815 20 179 405 ,1,380 3,100, 855 20 ,231 500 2,005 a,s10,- s15 20 ,075 2,570 3,825 Y 705 20 239 713 2,810 3,795 755 om theceiiam l er e p e" set ort 19my g specific embodiments of the inventionjit is e. .7 the. th ipr anie acid de retive th product formed by reacting carbondisulfide'with the reaction product .0 g r l aldehyde aha-anamphatic cyclic secondary lie comprise an efiec- -tiregr upofyulean z c ce er o s;whi hare 3Z5 .-,rapid 'in their accelerating action and; are;

v -prises heating rubber and sulfurin the'presence of an acceleratoncomprising the acetic acid de- :'-heating rubber andgsulfur the presence of an accelerator comprising the vreaction product-of -substantiallyiequi-molecular proportions of acetic iacid'and-the :product formedrby reacting substan- .ctially equi-molecular V proportions of v methylene 50 dipiperidine and carbonidisulfide.

6."A.-proccss of treating irubber which'comprises heating rubber and :sulfur in .the presence -ofan-j-accelerator :comprising an aliphatic organic acid derivativeofthe product formed by 2555 .1 reacting v substantially equiemolecular :proportions of carbon disulfiderand :an :alkylideneidi- H piperidine. t 1

7.-A process of vtreating rubber:which comrivative of'theproductiormed by reacting substantially :equi-molecular proportions of :carbon disulfide and an-alkylidene dipiperidine.

--8-.-The vulcanized rubberproduct producedby 65 i heating rubber and sulf ur'inithe presence of an vaccelerator comprising an organic acid Yderivativev of A the product formed Iby reacting substantially;;equi molecular proportions of 1 carbon disulfide and the reaction product of;substantially on olecularrp op rt 1f a ralipha iee ehyde and substantially two molecular proportipns gof an aliphatic cyclic 5 secondary amine, I

9. The; vulcanized rubber product produced'by "heatingrubber and. sulfur gthepresence of an 15 accelerator comprising an organic acid derivative of the product formed by reacting substantially equi-molecular proportions of carbon di-' sulfide and the reaction product of substantially one molecular proportion of an aliphatic aldehyde and substantiallytwo molecular proportions of a piperidine.

10. The vulcanized rubber product produced by heating rubber and sulfur in the presence of anaccelerator comprising analiphatic organic acid derivative of the product formedby reacting substantially equi-molecular proportions of carbon disulfide and the reaction product of substantially one molecular proportion of an aliphatic aldehyde and. substantially two molecular proportions of a piperidine.

11. The vulcanized rubber product produced by heating rubber and sulfur in the presence of ,an accelerator comprising the acetic acid derivative of the product formed by reacting substantially equi-molecular proportionsfiof carbon disulfide and methylene dipiperidine.

12. The vulcanized rubber product produced by heating rubber and sulfur in the presence of an accelerator comprising the reaction product of substantially equi-molecular proportions of acetic acid and the product formed by reacting substantially equi-molecular proportions of fmethylene dipiperidine and carbon disulfide.

13. The vulcanized rubberproduct produced by heating rubber and sulfur in the presence of an accelerator comprising an aliphatic organic acid derivative of the product formed by reacting substantially equi-molecular proportionsof CHESTER WM; CHRISTENSEN. 

